Open the resulting folder and choose the version of the mask you want to install.
Select that folder and copy it into the "mod_overrides" folder inside the "assets" folder of the directory of PAYDAY 2 (If you don't have "mod_overrides" just make it).
Done. Open the game.
Notes:
Re-distribution in any way of our mods is strictly FORBIDDEN without our explicit consense. If you want to share our mods somewhere else, please contact us at our website and wait for a response.